Display calibration systems and related methods
First Claim
1. A display device, comprising:
- an array of LEDs configured to produce light for the display device;
a memory configured to store correction coefficients, which are associated with the array of LEDs and used to compensate for variations in the light produced by the array of LEDs;
sense circuitry configured for measuring a photo-sensitivity of an LED within the array of LEDs by measuring an open circuit voltage and a short circuit current induced across the LED when the LED is illuminated with a light source; and
control circuitry configured to adjust output power from the LED by;
comparing the measured short circuit current with a short circuit current measurement previously determined while illuminating the LED with the light source to provide an indication of a variation in intensity of light produced by the LED over time;
modifying one or more of the correction coefficients associated with the LED when a difference exists between the measured short circuit current and the previously determined short circuit current measurement; and
when the one or more correction coefficients are modified, using the modified correction coefficients to adjust the output power from the LED by adjusting a current applied to the LED.
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Accused Products
Abstract
Display calibration systems and related methods are disclosed that use photo-sensitivity of LEDs to correct for variations between LEDs during initial production and over lifetime for display systems. The display devices include arrays of LEDs and use photo-sensitivity of the LEDs to correct for variations between LEDs. Such LED arrays can produce images directly as in LED billboards and sports arena scoreboards, and smaller Organic LED (OLED) displays, or can produce the backlight for LCD screens for instance. Variations in LED brightness and color can be compensated for in order for such a display to have uniform color and brightness. This compensation is performed in the embodiments disclosed by measuring the signal induced on each LED by uniform incident light as a measurement of the photo-sensitivity of the LEDs.
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Citations
44 Claims
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1. A display device, comprising:
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an array of LEDs configured to produce light for the display device; a memory configured to store correction coefficients, which are associated with the array of LEDs and used to compensate for variations in the light produced by the array of LEDs; sense circuitry configured for measuring a photo-sensitivity of an LED within the array of LEDs by measuring an open circuit voltage and a short circuit current induced across the LED when the LED is illuminated with a light source; and control circuitry configured to adjust output power from the LED by; comparing the measured short circuit current with a short circuit current measurement previously determined while illuminating the LED with the light source to provide an indication of a variation in intensity of light produced by the LED over time; modifying one or more of the correction coefficients associated with the LED when a difference exists between the measured short circuit current and the previously determined short circuit current measurement; and when the one or more correction coefficients are modified, using the modified correction coefficients to adjust the output power from the LED by adjusting a current applied to the LED. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A method for operating a display device having an array of LEDs configured to produce light for the display device, and a memory for storing correction coefficients, which are associated with the array of LEDs and used to compensate for variations in the light produced by the array of LEDs, the method comprising:
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measuring a photo-sensitivity of an LED within the array of LEDs by measuring an open circuit voltage and a short circuit current induced across the LED when the LED is illuminated with a light source; comparing the measured short circuit current to a short circuit current measurement previously determined while illuminating the LED with the light source to provide an indication of a variation in intensity of light produced by the LED over time; modifying one or more of the correction coefficients associated with the LED when a difference exists between the measured short circuit current and the previously determined short circuit current measurement; and when the one or more correction coefficients are modified, using the modified correction coefficients to adjust an output power from the LED by adjusting a current applied to the LED. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44)
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Specification